*{
    margin: 0;
    padding: 0;
    list-style: none;
}
#tab {
    width: 600px;
    height: 300px;
    border: 1px solid #ccc;
}
.tab_content > div{
    display: none;
}
.tab_content .active{
    display:block;
}
.tab_header ul{
    height: 50px;
    line-height: 50px;
    border-bottom: 1px solid #ccc;
}
.tab_header li {
    float: left;
    width: 200px;
    text-align: center;;
}
.tab_header li.active{
    background: #ccc;
}